Field of the Invention
The present invention relates to a circuit-substrate supporting device that supports a circuit substrate by using a supporting member or the like, and a battery unit with the circuit-substrate supporting device.
Description of the Related Art
Well-known battery units include battery packs and the like in which batteries, such as lithium-ion secondary batteries and nickel-hydrogen secondary batteries, and a circuit substrate mounted with a battery protection circuit and the like are built into a housing as a unit. In a battery unit like this, a circuit substrate is generally installed adjacent to batteries while being supported by a supporting member, such as a battery holder and a substrate holder (see Unexamined Japanese Patent Publication No. 10-12201 or 2006-164601).
In the conventional battery unit, the circuit substrate is supported by a single supporting member that is larger than the outer shape of the circuit substrate (that is of a size encompassing the outer shape of the circuit substrate) in order to firmly support the circuit substrate.
In the conventional battery unit, the supporting member of the circuit substrate is generally made by molding an insulating material such as plastic to prevent a short circuit of an electronic circuit constructed in the circuit substrate, and the like. On the other hand, there is the possibility that a supporting member like this might be bent and deformed by a remaining stress from the molding. For that reason, in the conventional battery unit where the circuit substrate is supported by a single supporting member that is larger than the outer shape of the circuit substrate, a bending stress sometimes acts upon the circuit substrate due to the bent and deformed supporting member, which might cause a deformation such as warping, fracture or the like in the circuit substrate.